From b2ad0be169b45595284a87281dbf0c921d40e24d Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Wed, 31 Aug 2016 23:07:21 +0100
Subject: [PATCH] Fix launcher failure when MP is enabled.
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

Only set —callsign argument if the user entered one.
---
 src/GUI/QtLauncher.cxx | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/GUI/QtLauncher.cxx b/src/GUI/QtLauncher.cxx
index e56db78c7..16307ecf9 100644
--- a/src/GUI/QtLauncher.cxx
+++ b/src/GUI/QtLauncher.cxx
@@ -886,7 +886,11 @@ void QtLauncher::onRun()
     }
 
     if (m_ui->mpBox->isChecked()) {
-        opt->addOption("callsign", m_ui->mpCallsign->text().toStdString());
+        std::string callSign = m_ui->mpCallsign->text().toStdString();
+        if (!callSign.empty()) {
+            opt->addOption("callsign", callSign);
+        }
+
         QString host = m_ui->mpServerCombo->currentData().toString();
         int port = 5000;
         if (host == "custom") {
-- 
2.39.5